1. Technical Field
The present invention generally relates to printers and, more particularly, to ink supply systems for thermal inkjet printers.
2. Background Art
In thermal inkjet printers, systems must be provided for supplying ink to printing elements. Typically, the ink supply systems include ink supply chambers that act as ink reservoirs. To prevent ink from drying in the supply chambers, it is known to place sponge-like materials in the chambers to hold ink. It is also known to place collapsible bladders in supply chambers to hold ink.
There are several shortcomings in ink supply systems that are conventionally used in thermal inkjet printers. For example, sponge-like materials occupy substantial volume in ink supply chambers and, therefore, limit ink storage capacity. Moreover, the capillary-like action inherent in sponge-like materials creates back pressures that increase as ink is depleted. In some situations, back pressure may increase sufficiently to interfere with ink release in sufficient quantities to maintain high quality printing.
In view of the foregoing discussion, it can be appreciated that a need exists in the thermal inkjet printer art for systems that provide improved control of ink flow to printing elements.